Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M10/00—Secondary cells; Manufacture thereof
  • H01M10/05—Accumulators with non-aqueous electrolyte
  • H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
  • H01M10/0561—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of inorganic materials only
  • H01M10/0562—Solid materials
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M10/00—Secondary cells; Manufacture thereof
  • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
  • H01M10/4235—Safety or regulating additives or arrangements in electrodes, separators or electrolyte
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M6/00—Primary cells; Manufacture thereof
  • H01M6/14—Cells with non-aqueous electrolyte
  • H01M6/18—Cells with non-aqueous electrolyte with solid electrolyte
  • H01M6/182—Cells with non-aqueous electrolyte with solid electrolyte with halogenide as solid electrolyte
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M6/00—Primary cells; Manufacture thereof
  • H01M6/14—Cells with non-aqueous electrolyte
  • H01M6/18—Cells with non-aqueous electrolyte with solid electrolyte
  • H01M6/185—Cells with non-aqueous electrolyte with solid electrolyte with oxides, hydroxides or oxysalts as solid electrolytes
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M2300/00—Electrolytes
  • H01M2300/0017—Non-aqueous electrolytes
  • H01M2300/0065—Solid electrolytes
  • H01M2300/0068—Solid electrolytes inorganic
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M2300/00—Electrolytes
  • H01M2300/0017—Non-aqueous electrolytes
  • H01M2300/0065—Solid electrolytes
  • H01M2300/0068—Solid electrolytes inorganic
  • H01M2300/0071—Oxides
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
  • Y02E60/10—Energy storage using batteries

Definitions

• the present disclosure relates to self-charging and/or self-cycling electrochemical cells containing a solid glass electrolyte.
• An electrochemical cell has two electrodes, the anode and the cathode, separated by an electrolyte.
• materials in these electrodes are both electronically and chemically active.
• the anode is a chemical reductant and the cathode is a chemical oxidant. Both the anode and the cathode are able to gain and lose ions, typically the same ion, which is referred to as the working ion of the battery.
• the electrolyte is a conductor of the working ion, but normally it is not able to gain and lose ions.
• the electrolyte is an electronic insulator, it does not allow the movement of electrons within the battery.
• both or at least one of the anode and the cathode contain the working ion prior to cycling of the electrochemical cell.
• the electrochemical cell operates via a reaction between the two electrodes that has an electronic and an ionic component.
• the electrolyte conducts the working ion inside the cell and forces electrons also involved in the reaction to pass through an external circuit.
• a battery may be a simple electrochemical cell, or it may be a combination of multiple electrochemical cells.
• the present disclosure provides an electrochemical cell including a solid glass electrolyte including an alkali metal working ion that is conducted by the electrolyte, and a dipole, an anode having an effective anode chemical potential ⁇ ⁇ , and a cathode having an effective cathode chemical potential ⁇ .
• a solid glass electrolyte including an alkali metal working ion that is conducted by the electrolyte, and a dipole
• an anode having an effective anode chemical potential ⁇ ⁇
• a cathode having an effective cathode chemical potential ⁇ .
• an electric double-layer capacitor is formed at one or both of an interface between the solid glass electrolyte and the anode and an interface between the solid glass electrolyte and the cathode due to a difference between ⁇ ⁇ and ⁇ .
• the electrochemical cell may have any or all combinations of the following additional features, unless such features are clearly mutually exclusive: a) at least one or both of the cathode and the anode may include a metal; b) at least one or both of the cathode and anode may consist essentially of or consist of a metal; c) both the cathode and the anode may substantially lack the working ion prior to an initial charge or discharge of the electrochemical cell; d) one of the cathode and the anode may include, consists essentially of, or consist of a metal and the other may include a semiconductor; e) one or both of the cathode and the anode may include a catalytic molecular or particle relay that determines its effective chemical potential; f) the working ion may include lithium ion (Li + ), sodium ion (Na + ), potassium ion (K + ) magnesium ion (Mg 2+ ), Aluminum (Al 3+ ), or any combinations
• the present disclosure further includes a battery containing one electrochemical cell as described above, or at least two such cells, which may be in series or in parallel.
• Electrochemical cells and batteries disclosed above and elsewhere herein may be rechargeable.
• FIG. 1A is a schematic, cross-sectional diagram of an electrochemical cell according to the present disclosure prior to the first charge at open circuit.
• FIG. IB is a schematic, cross-sectional diagram of the electrochemical cell of
• FIG. 1 A during a self-charge.
• FIG. 1C is a schematic, cross-sectional diagram of the electrochemical cell of FIG. 1 A and FIG. IB during discharge.
• FIG. 2 is a schematic diagram of an equivalent circuit that may be used to calculate the time dependence of the evolution of the measured voltage at open-circuit of the electrochemical cell of FIG. 1A.
• FIGs. 3A-3D are a series of graphs of test results for an electrochemical cell having an Al-C anode, a S-C-Cu cathode and a Li+ solid glass electrolyte containing 10% Li 2 S. Measured voltage is designated Vme(t). Measured current is designated Ime(t). Control current is designated Icon(t) and is -1 ⁇ versus time (t) after a short charge (vertical line on left in FIG. 3A).
• Vme(t) Measured current
• Ime(t) Control current
• Icon(t) Control current is designated Icon(t) and is -1 ⁇ versus time (t) after a short charge (vertical line on left in FIG. 3A).
• FIG. 3A presents results for an electrochemical cell allowed to self-charge without cycling for 41 hours followed by self-cycling for 27 hours with a cycling period of about 8 min.
• FIG. 3B presents an expanded time-scale graph of the period of the graph of FIG. 3 A between 40 and 42 hours.
• FIG. 3C presents results from a second cycle of the electrochemical cell of FIGs. 3 A and 3B after a second short charge while the electrochemical cell is heated, beginning at 20.5 hours from 12 °C to 22 °C over a two-hour period, followed by slow cooling.
• FIG. 3D presents an expanded time-scale graph of the period of the graph of FIG. 3C during which the electrochemical cell is heated.
• FIG. 4 is graph of measured discharge voltage versus time after closing the circuit of an electrochemical cell with a Li anode, a C-Ni mesh cathode, and a Li+ solid glass electrolyte.
• the cycling period of self-cycling is 24 hours.
• FIG. 5A is a graph of test results for an electrochemical cell having an an Al-C anode, a S-C-Cu cathode and a Li + solid glass electrolyte containing 10% Li 2 S. Measured voltage is designated V me (t)- Measured current is designated I me (t)- Control current is designated I CO n(t) and is 0.2 mA during charge and -1 ⁇ during self-charge.
• FIG. 5B presents an expanded current axis for a portion of the graph of FIG. 5A.
• FIG. 6 is a graph of the measured first discharge current versus time after closing the circuit of a jelly roll electrochemical cell with an Al-C anode, a Cu cathode, and a Li+ solid glass electrolyte. Discharge was with a low load resistance.
• FIG. 7 is a graph of the measured voltage versus time over a 5 -hour charge/5 - hour discharge cycle for an electrochemical cell with a Li anode, a yMn0 2 -C-Li glass- Cu cathode, and a Li+ solid glass electrolyte.
• the electrochemical cell was cycled for 190 days. Peak voltages are indicated by arrows.
• the present disclosure relates to an electrochemical cell including a solid glass electrolyte that contains electric dipoles as well as the working ion and that is able to reversibly plate the working ion on either electrode without being resupplied by the other electrode, which causes the electrochemical cell to exhibit a self-charge and a self-cycling behavior.
• the cell has a solid electrolyte containing, typically, not only mobile alkali metal working cations that can be plated dendrite free on a metallic current collector, but also slower moving molecular electric dipoles.
• a difference in the electrochemical potentials of the two electrodes is a driving force to create, at open-circuit, an electric-double-layer capacitor at each electrode/electrolyte interface as in a normal electrochemical cell.
• the difference in the translational mobilities of the working cations and of the orientational and translational mobilities of the electric dipoles creates a slower formation of any excess charge in the electrolyte at the interface.
• the dipole contribution to the interface charge may be large enough to induce plating of the working cation as an alkali-metal layer on the anode, which represents a self-charge.
• the electrolyte becomes charged negatively until an equilibrium between plating and stripping is reached.
• the charge in the electrolyte is represented in an equivalent circuit as an inductor in parallel with a capacitor, which can create a self-cycling component of a charge or discharge current and/or voltage at a fixed control current imposed by an external potentiostat.
• the electrolyte is referred to as glass because it is amorphous, as may be confirmed through X-ray diffraction.
• the working ion may be an alkali-metal cation, such as Li + , Na + , K + , or a metal cation, such as Mg 2+ , and/or Al 3+ .
• Self-charging refers to a phenomenon, as described further herein, in which, an electrochemical cell contains electrodes that, on fabrication, do not contain the working ion of the cell and yet delivers a discharge current on closing the external circuit without ever having received a charging current from an external source.
• This phenomenon is the result of an alignment and displacement of electric dipoles within the electrolyte after cell assembly as a result of dipole-dipole interactions and an internal electric field.
• the internal electric field provided by the dipole alignment is large enough to plate the working ion as a metal from the electrolyte on one of the electrodes without resupply to the electrolyte from the other electrode, thereby charging the electrolyte negative.
• the working ions are returned to the electrolyte and electrons are sent to the external circuit where they provide a discharge current.
• Self cycling occurs where the working ion of the electrolyte is plated on an electrode, which charges the electrolyte negative.
• the negative charge in the electrolyte when large enough, strips the plated metal back to the electrolyte as cations and releases electrons to the external circuit.
• the different rates of response of the dipoles and ions in the electrolyte and the electrons to the external circuit result in a cycling of the currents in the external circuit and/or the cell voltage.
• both self-charging and self-cycling behaviors may occur without an external energy input, both phenomena may also occur as a component of the cell charge/discharge performance with an external charge/discharge input.
• a self-charging electrochemical cell may be provided with a charging current as an external energy input, in which case it will exhibit a greater charge than is dictated by the charging current to give a coulomb efficiency greater than 100%.
• the discharge current and/or voltage may have a self-cycling component of frequency that is different from the charge/discharge cycling frequency.
• the solid glass electrolyte of this disclosure is non-flammable and is capable of plating dendrite-free alkali metals on an electrode current collector and/or on itself; the atoms of the plated metal come from the working ion of the electrolyte; the plated working ions may or may not be resupplied to the electrolyte from the other electrode.
• an alkali-metal cation such as Li + , Na + , K +
• a metal cation such as Mg 2+ , Al 3+
• electric dipoles such as A 2 X or AX ⁇ , or MgX or A1 2 X 3
• Suitable A + -glass electrolytes and methods of making them have been previously described in WO2015 128834 (A Solid Electrolyte Glass for Lithium or Sodium Ion Conduction) and in W02016205064 (Water- Sol vated Glass/ Amorphous Solid Ionic Conductors), where the alkali-metal -ion disclosures of both are incorporated by references therein.
• the glass may also contain as additives up to 50 w% of other electric-dipole molecules than those formed form the precursors used in the glass synthesis without dipole additives.
• the presence of the electric dipoles gives the glass a high dielectric constant; the dipoles are also active in promoting the self-charge and self-cycling phenomenon.
• the solid glass electrolytes are not reduced on contact with metallic lithium, sodium, or potassium and they are not oxidized on contact with high-voltage cathodes such as the spinel Li[Ni 0 5 Mni 5 ]0 4 or the olivines LiCo(P0 4 ) and LiNi(P0 4 ). Therefore, there is no formation of a passivating solid- electrolyte interphase (SEI).
• the surfaces of the solid-glass electrolytes are wet by an alkali metal, which allows plating from the glass electrolyte dendrite-free alkali metals that provide a low resistance to transfer of ions across an electrode/electrolyte interface over at least a thousand, at least two thousand, or at least five thousand charge/discharge cycles.
• the solid glass electrolyte may be applied as a slurry over a large surface area; the slurry may also be incorporated into paper or other flexible cellulose or polymer membranes; on drying, the slurry forms a glass.
• the membrane framework may have attached electric dipoles or, on contact with the glass, forms electric dipoles that have only rotational mobility.
• the electric dipoles within the glass may have translational as well as rotational mobility at 25°C. Reactions between the dipoles with
• translational mobility may form dipole-rich regions within the glass electrolyte with some dipole condensation into ferroelectric molecules; the coalescence of the dipoles, which is referred to as aging of the electrolyte, may take days at 25°C, but can be accomplished in minutes at 100°C.
• An electrode consists of a current collector and/or a material having an active redox reaction.
• An electrode current collector is a good metal such as Al or Cu; it may also be a form of carbon, an alloy, or a compound such as TiN or a transition-metal oxide.
• the current collector may be an electrode without an active material on it or it may transport electrons to/from an active material on it; the active material may be an alkali metal, an alloy of the alkali metal, or a compound containing an atom of the working ion of the electrolyte.
• the current collector transports electrons to or from the external circuit and to or from my active material of an electrode reacts with the working ion of the electrolyte by having electronic contact with the current collector and ionic contact with the electrolyte.
• the ionic contact with the electrolyte may involve only excess or deficient working-ion concentration at the electrode/electrolyte interface, which creates an electric-double-layer capacitor (EDLC), or it may also involve formation of a chemical phase at the electrode surface.
• EDLC electric-double-layer capacitor
• electrochemical cell are, on fabrication, only current collectors containing no detectable atom of the working ion of the electrolyte down to 7000 ppm by, for example, atomic absorption spectroscopy. However, after cell assembly, atoms of the working ion of the electrolyte may be detected on the electrode by atomic absorption spectroscopy or by other means.
• one or both electrodes of the cell may contain an additional electronically conductive material such as carbon that aids plating of the working cation on the current collector without changing significantly the effective Fermi level of the composite current collector.
• the solid glass electrolyte may have a large dielectric constant, such as a relative permittivity (GR) of 10 2 or higher.
• Solid glass electrolytes are non-flammable and may have an ionic conductivity GA for the working ion A + , of at least 10 "2 S/cm at 25 °C. This conductivity is comparable to the ionic conductivity of the flammable conventional organic-liquid electrolytes used in Li-ion batteries, which makes the cells safe.
• the solid glass electrolyte may be formed by transforming a crystalline electronic insulator containing the working ion or its constituent precursors (typically containing the working ion bonded to O, OH, and/or a halide) into a working-ion- conducting glass/amorphous solid. This process can take place in the presence of dipole additives as well.
• the working ion-containing crystalline, electronic insulator or its constituent precursors may be a material with the general formula A 3-x H x OX, wherein 0 ⁇ x ⁇ 1, A is at least one alkali metal, and X is the at least one halide.
• Water may exit the solid glass electrolyte during its formation.
• E c is the bottom of the conduction band and E c > ⁇ , where ⁇ is the anode chemical potential.
• Ey is the top of the valence band and Ey ⁇ ⁇ , where ⁇ c is the cathode chemical potential.
• the energy difference ⁇ - ⁇ may drive the self-charging and self-cycling behaviors.
• the dipoles contribution causes the electrochemical cell to have a capacitance at open or closed circuit that is higher than in an otherwise identical electrochemical cell with an electrolyte other than a solid glass electrolyte as disclosed herein.
• An electrochemical cell containing the solid glass electrolyte as disclosed herein may also be able to plate and strip the working ion from one or both electrodes such that an electrolyte-electrode bond between the electrolyte and at least one electrode is sufficiently strong for electrolyte volume changes during cycling to be substantially perpendicular to the interface between the electrolyte and the electrode.
• the bond will be sufficiently strong between the electrolyte and both electrodes for the electrolyte volume changes to be substantially perpendicular to both interfaces between the electrolyte and both electrodes.
• a control current I con is the current specified by the potential difference between the two electrodes controlled by a load in a potentiostat
• the measured current I mc is the actual measured current, which includes the current specified by the potentiostat and the current resulting from the self-charge.
• the current resulting from the self-charge may be in the same or the opposite direction of Icon on discharge.
• the subscript dis and ch are added to specify whether we refer to discharge or charge currents and voltages.
• An electrochemical cell as disclosed herein may have a measured discharge current Ims-dis and/or a measured charging current I me-Ch less than the control current
• an electrochemical cell as disclosed herein may have a charging current I Ch that is greater than the control current I con .
• an electrochemical cell as disclosed herein may have a measured discharge current I me -di S that is larger than the discharge control current la s -con- Such an electrochemical cell, in addition to normal discharge, may exhibits self-cycling of both the measured discharge current I me . dls and voltage V me . dis
• An electrochemical cell as disclosed herein may, at open-circuit, develop a voltage that is less than or equal to the theoretical voltage as a result of the difference in the electrode electrochemical potentials.
• An electrochemical cell as disclosed herein may have a self-voltage sufficiently large to cause a working ion in the electrolyte to plate onto the anode at open-circuit. Moreover, the electric power delivered by the self-charge may be sufficient to light a red LED for over a year.
• An electrochemical cell as disclosed herein may exhibit plating of the ion on either electrode current collector when subjected to a constant I con or V con - Plating of the working cation from the electrolyte without being resupplied by the counter electrode may result in a self-cycling component of the measured current I me and measured voltage V me .
• a control current I cm is the current specified by the potential difference between the two electrodes controlled by a load in a potentiostat
• the measured current I me is the actual measured current, which includes the current specified by the potentiostat and the current resulting from the self-charge.
• the current resulting from the self-charge may be in the same or the opposite direction of Icon on discharge.
• the subscripts dis and ch are added to specify whether we refer to discharge or charge currents and voltages.
• An electrochemical cell as disclosed herein may exhibit self-cycling at a given cycle period. Due to self-charging, the period of the self-cycling is independent of charge/discharge period.
• the measured current I me of an electrochemical cell as described herein contains both direct current and alternating current components. In some applications, only the alternating-current portion may be used, for example in signaling.
• the alternating current period is the self-cycling period which may have a period of between minutes and days.
• FIG. 1 includes FIG. 1A to illustrate the electrochemical cell 100 prior to cycling, FIG. IB to illustrate the electrochemical cell 100 during self-charge, and FIG. 1C to illustrate the electrochemical cell 100 during discharge.
• electrochemical cell 100 contains anode 10 with contact 15, cathode 20 with contact 25, and solid alkali-metal-ion glass electrolyte 30. Excess working ions in electrolyte 30 are represented by + circles.
• Depletion of working ions in electrolyte 30 are represented by - circles.
• Electric dipoles in electrolyte 30 are represented by +/- ellipses.
• Electronic charges in the electrodes are represented by + and - circles.
• arrows attached to circles represent directions of motion of the charges associated excess mobile cations or deficiency of mobile cations in the electrolyte, electrons in the electrode.
• FIG. 1 A illustrates schematically electrochemical cell 100 at open-circuit.
• the chemical potential ( ⁇ ⁇ ) of anode 10 is higher than the chemical potential ( ⁇ ) of cathode 20.
• electric double-layer capacitors 40a and 40b are formed at the interfaces between the electrodes and the electrolyte. Energy for the formation of these electric double-layer capacitors 40a and 40b is supplied by the differences in chemical potentials of anode 10 and cathode 20.
• One such electrochemical cell 100 may have an alkali metal anode 10 and a Cu cathode 20, with an alkali-metal working ion (A + ) in the solid glass electrolyte 30.
• Displacement of the working ion (A + ) and the electric dipoles in solid glass electrolyte 30 allows the formation of electric double-layer capacitors 40a and 40b.
• electric double-layer capacitor 40a at the interface of anode 10 (which is the negative terminal of electrochemical cell 100) and electrolyte 30 has an excess of working ions in electrolyte 30 (represented as +), which results from the shift of those working ions in electrolyte 30 towards its anode side.
• the portion of anode 10 at the interface will have an excess of negative electronic charge, (represented as -), with a compensatory excess of positive cation charge on the electrolyte side of the interface between anode (1) and electrolyte 30 that are separated from one another.
• Electric double-layer capacitor 40b at the interface of cathode 20 (which is the positive terminal of electrochemical cell 100) and electrolyte 30 has a depletion of working cations in electrolyte 30 (represented as -), which results from the shift of working ions in the electrolyte 30 towards its anode side and away from its cathode side.
• the portion of cathode 20 at the interface will have a compensatory excess of positive electronic charge (represented as +), in cathode 20 distant from the interface with electrolyte 30.
• electrolyte 30 will have a neutral net charge.
• Increased dipole alignment also strengthens the electric field across electrolyte 30 and drives further dipole alignment and movement.
• Maximum alignment and motion in a given electrochemical cell 100 may be assumed to have occurred when V oc ceases to change in a consistent direction over time, or during a given period of time, such as for at least one minute or at least five minutes for alignment and days or minutes for movement depending on the temperature.
• the additional electric field created by dipole alignment and motion in electrolyte 30 may be sufficient to even drive plating of the working ion on anode 10 when electrochemical cell 100 is at open-circuit.
• the net negative charge that electrolyte 30 develops as a result of this plating process will be sufficiently high that it cannot be overcome by the electric field and plating on anode 10 will cease.
• FIG. IB illustrates electrochemical cell 100 when its circuit is first closed, for example by connecting an external circuit to contacts 15 and 25.
• the external circuit includes a potentiostat that imposes a charging control current I con that may be less than some critical current I c .
• the critical current is the maximum I CO n-dis at which self- charge phenomenon still exist as shown in Fig. IB.
• the energy stored in electric double-layer capacitors 40a and 40b and by the aligned dipoles in electrolyte 30 introduces a charging current I Ch . This phenomena self- charges electrochemical cell 100.
• Cathode 20 lacks the working ion, so it cannot resupply working ions as they are depleted from electrolyte 30 to form plated metal 50. Accordingly, the electrolyte 30 at the interface with anode 10 becomes increasingly negatively charged, eventually reaching the point where the working ion is no longer being plated on anode 10 as plated metal 50 and the working ions begin to be stripped back to the electrolytes.
• the plated metal may become so thick that the electrode chemical potential becomes that of the plated metal so rather than that of the current collector, 10, which makes it more difficult to plate the working cation from the electrolyte as the metal 50, thereby terminating the plating process.
• the measured charging current I me -ch decreases.
• the cycle period may be on the order of minutes, between one and ten minutes.
• FIG. 1C illustrates electrochemical cell 100 during discharge through an external circuit that includes a potentiostat that imposes a control current I con that is greater than the critical current I c , as in a low-load external circuit, such as might include a light-emitting diode (LED).
• a potentiostat that imposes a control current I con that is greater than the critical current I c
• a low-load external circuit such as might include a light-emitting diode (LED).
• LED light-emitting diode
• a current 1 ⁇ 2 8 is created and may be controlled by ⁇ ⁇ ⁇
• the load of the external circuit is sufficiently low for electrons to flow from anode 10 to cathode 20 to attract working ions from electrolyte 30 to cathode 20, where they combine with the electrons and form plated metal 60 on cathode 20.
• the transfer of electrons from anode 10 to cathode 20 reduces both electric double-layer capacitors 40a and 40b, but it primarily reduces electric double-layer capacitor 40b, at the electrolyte-cathode interface. This lowers the electric field across electrolyte 30, allowing the working ion to be plated on cathode 20.
• electric double-layer capacitor 40b is depleted, it is typically not destroyed so long as the majority of the dipoles in electrolyte 30 remain oriented in the same way as when electrochemical cell 100 is at open circuit.
• the dipoles in electrolyte 30 are, however, compressed in direction 80.
• Anode 10 substantially lacks the working ion, so it cannot resupply working ions as they are depleted from electrolyte 30 to form plated metal 60.
• changes in the internal electric field of electrolyte 30 that are created by electron transfer that occurs much faster than the working ion and electric dipoles can redistribute and align to accommodate them. Accordingly, the electrolyte 30 at the interface with cathode 20 becomes increasingly negatively charged, eventually reaching the point where the working ion is also stripped from plated metal 60 and returned to electrolyte 30, resulting in a measured discharge current I me that is increasingly lower until it reaches I me minimum until plating and stripping are in equilibrium.
• plated metal 60 may eventually become so thick, electrolyte 30 is effectively screened from cathode 20 and working ions in electrolyte 30 are substantially all exposed to plated metal 60 which does not have a sufficient difference in chemical potential as compared to anode 10 to cause additional plating based on the difference in chemical potential alone or combined with any remaining electric field in electrolyte 30. In such cases, the working ion may no longer be plated to cathode 20 as plated metal 60.
• the process reverses and working ions are once again plated on cathode 20 as metal plate 60.
• This alteration between plating and stripping of the working ion from plated on metal 60 on cathode 20 results in self-cy cling of electrochemical cell 100, with concurrent cycling of the voltage and I me -
• This self-cy cling occurs with a given cycle period that tends to remain constant as long as cycling continues.
• the cycle period depends on the rate of compression in direction 80 of the dipoles in electrolyte 30 during discharge and their expansion during charge. Typically increasing I me towards maximum is faster than decreasing it to minimum.
• the period may be on the order of days, such as one and seven days.
• Electrons can only pass one way through an LED. Accordingly, in actual use of electrochemical cell 100, anode 10 is increasingly positively charged and cathode 20 is increasingly negatively charged until the electric field across electrolyte 30 reverses the orientation of the electric dipoles, which then switches off the current that flows through the load. For electrochemical cells with a small I me , the time required for this to occur may be lengthy, even more that a year. Thus, an electrical device may be powered by electrochemical cell 100 for that length of time with no external energy input.
• an external charging current I C h may create large electric double layer capacitors 40a and 40b, which may cause the working ion to plate from electrolyte 30 onto anode 10, as such plating occurs during charging of a conventional rechargeable electrochemical cell.
• depletion of the working ion from the electrolyte 30 with no resupply from cathode 20 in contrast to a conventional rechargeable electrochemical cell in which such resupply does occur, causes increasing resistance to further plating on anode 10 as negative charge in electrolyte 30 near anode 10 increases.
• average I me . c h may be greater than or equal to I CO n-ch while the working ion is being stripped from and plated to anode 10.
• the electric double-layer capacitor 40a near anode 10 is also being charged.
• electric double-layer capacitor 40a is charged sufficiently for the negative charge on the anode side to block the return of electrons to anode 10, thereby preventing further stripping of the working ion from anode 10. At this point, continued charging can only charge the electric double-layer capacitor 40a.
• an inductance is introduced into the equivalent circuit to represent the role of the negative charge introduced into electrolyte 30 by plating of the working cation from the electrolyte without a resupply to the electrolyte from a counter-cation.
• Electrochemical cells of the present disclosure may be used in batteries.
• Such batteries may be simple batteries containing few components other than an electrochemical cell and a casing or other features.
• Such batteries may be in standard battery formats, such as coin cell, standard jelly roll, pouch, or prismatic cell formats. They may also be in more tailored formats, such as tailored prismatic cells.
• Electrochemical cells of the present disclosure may also be used in more complex batteries, such as batteries containing complex circuitry and a processor and memory computer-implemented monitoring and regulation. Regardless of simplicity, complexity, or format, all batteries using electrochemical cells of the present disclosure may exhibit improved safety, particularly a lower tendency to catch fire when damaged, as compared to batteries with organic-liquid electrolytes.
• a battery may contain a single electrochemical cell as disclosed herein, or two or more such cells, which may be connected in series or in parallel.
• Electrochemical cells as disclosed herein and batteries containing them may be rechargeable.
• Electrochemical cells of the present disclosure may also be used in devices that take advantage of the electric double-layer capacitor, such as in capacitors. They may also be used in devices that take advantage of the cycle period, particularly the AC period, such as signaling devices.
• electrochemical cells of the present disclosure may be used as a dielectric gate of a field-effect transistor; in portable, hand-held and/or wearable electronic device, such as a phone, watch, or laptop computer; in a stationary electronic device, such as a desktop or mainframe computer; in an electric tool, such as a power drill; in an electric or hybrid air, land or water vehicle, such as a boat, submarine, bus, train, truck, car, motorcycle, moped, powered bicycle, aircraft, drone, other flying vehicle, and toy versions thereof; for other toys; for energy storage, such as in storing electricity from wind, solar, hydropower, wave, or nuclear energy and/or in grid storage or as a stationary power store for small-scale use, such as for a home, business, or hospital; for a sensor, such as a portable medical or environmental sensor; to generate a low frequency electromagnetic wave, such as for underwater communication; as a capacitor, such as in a supercapacitor or a coaxial cable; or as a transducer.
• FIG. 3 presents results of an experiment demonstrating self-charge and self- cycling of an electrochemical cell with an Al-C anode, a S-C-Cu cathode and a Li + solid glass electrolyte containing 10 wt% Li 2 S (an Al-C/Li+ -glass/S-C-Cu cell).
• the Al anode had a carbon layer (Al-C) contacting the Li-glass electrolyte.
• the cathode was a Cu current collector with a carbon layer containing a sulfur relay contacting the Li-glass electrolyte.
• the measured voltage of the electrochemical cell versus time showed, after 6 h 26 min, a charge of 0.5 mA for 25 min that was followed by an abrupt discharge of the electric double-layer capacitors.
• the voltage at a constant I con increased little for the next 8 h 22 min as the electric double-layer capacitors were recharged, before increasing to 2.4 V with small-amplitude noise over the next 35 h 29 min.
• the measured voltage, V me of 2.4 V was the maximum voltage for self-charge plating of lithium metal Li° on the anode. A brief break in the rate of voltage increase occurred when V me is 2.2 V before oscillations begin.
• the theoretical V me for ( ⁇ - ⁇ ) ⁇ was 2.2 V.
• FIG. 3B shows an enlarged image of the onset of self-cycling between [ ⁇ 0- ⁇ ) - ⁇ ( ⁇ )]/ ⁇ and [ ⁇ ( ⁇ 1) - ⁇ ( ⁇ )]/ ⁇ in the measurement of FIG. 3A, allowing the oscillations to be more clearly seen.
• FIG. 3C shows the V me of the cell of FIG. 3 A in a second cycle at a constant Icon after an initial charge of Co 2 mA for 25 min.
• Li + from the glass electrolyte was plated on the Al anode after charging of the electric double-layer capacitors, and the Li + working ions were not resupplied to the electrolyte from the Cu cathode.
• V me of 1.65 V As further visible in enlarged FIG. 3D, a self- cycling with an average V me of approximately 1. 7 V began.
• V me A sharp drop in V me occurred when the temperature of the electrochemical cell was increased by heating from 12 °C to 26 °C. The electrochemical cell was then removed from the heater and allowed to return slowly to 12°. During cooling, V me increased to 2.1 V, the difference between the chemical potentials of Al and Cu. At that voltage, the electrochemical cell began to plate the working ion again, but without periodic cycling, until a small discharge occurred, followed by longer period cycling; a discharge of the electric double-layer capacitor to a V me of approximately 1.4 V occurred. At that point, plating resumed. Throughout these voltage changes, the measured charging current I me remained nearly constant, with only a small decrease during the final plating that was terminated abruptly at the final recorded discharge. The changes with temperature reflect the ionic and molecular motions in the electrolyte.
• Electrochemical cells with an electrochemical cell with an Al anode, a Cu cathode and a Li+ solid glass electrolyte were constructed and then connected in series to light a red LED in an external circuit. These cells exhibited self-charging with a discharge current, I dis that is greater than a critical current I c .
• the electrochemical cells had been previously cycled, but were not charged or otherwise supplied with an external energy input. The cells have powered the LED for approximately two years. Data per cell for the first year is presented in Table 1. The total density of energy delivered over the first year was 373.8 Wh/g.
• FIG. 4 presents the measured voltage V me (t) of a discharging electrochemical cell with a Li metal anode, a Li + glass electrolyte and a C-Ni cathode, with carbon located in a Ni mesh (Li-metal/Li+-glass/C-Ni cell).
• the load resistance was 1 mega ohm and the discharge current of approximately 2.5 ⁇ .
• the periodic hillocks in the voltage were the result of a periodic self-cycling of a self-charge component in the cell discharge compound.
• -Plating on the cathode had a longer period than plating on the anode (as shown in FIG. 3B). Due to the excess energy supplied by self-charging, the electrochemical cell exhibited a charge/discharge coulomb efficiency greater than 100% on cycling.
• FIG. 5 A presents data showing self-cy cling of a measured charging current
• the cells were recharged by an external power source after the first discharge.
• the measured voltage (Vme) was 2.1 V, corresponding to [ ⁇ ( ⁇ 1) - ⁇ ( ⁇ )]/ ⁇ .
• I me - Ch which was greater than I con , exhibited self-cycling with an amplitude such that I me - Ch remained greater than I con, as seen in FIG. 5B.
• Ime-c h remained greater than I CO n-c h , indicating that stripping of lithium metal from the cathode contributed to Ime-c h , with plating/stripping cycling that must result from an electrolyte charge localized near the interface of the electrolyte and the cathode because any possible resupply of Li + from the anode would take longer than the short self-cycling period.
• the average I me -c h remained constant until most, if not all of the lithium metal was stripped from the cathode and charging of the cathode electric double-layer capacitor commenced. There was no corresponding cycling of Vme because the cycling phenomena was localized to the cathode/electrolyte interface.
• FIG. 6 presents the measured discharge current I me of a jelly-roll Al-
• FIG. 7 shows the variation with time of the charge and discharge voltage on cycling an electrochemical cell with a Li anode, a Li + glass electrolyte, and a Mn0 2 - C-Li-glass-Cu cathode with a ⁇ 0 2 catalytic relay in a carbon layer contacting a Cu current collector (a Li/Li + -glass/Mn0 2 -C-Cu cell).
• Each cycle was 10 h 30 min for 444 cycles at a control current I con of 70 ⁇ and a measured discharge current I me of 53 ⁇ .
• Ime being less than I con indicates the presence of a self-charge current that opposed the discharge I CO n-
• the profile of V me showed cycling typical of self-charge via plating on the anode in excess of the Li + resupplied to the electrolyte via stripping from the cathode.
• the discharge voltage profile also showed a long cycle period of 34 days.

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• 2017
  • 2017-07-10 CN CN201780055483.7A patent/CN109964355A/zh active Pending
  • 2017-07-10 KR KR1020197003915A patent/KR20190032417A/ko not_active Application Discontinuation
  • 2017-07-10 JP JP2019500623A patent/JP2019522369A/ja active Pending
  • 2017-07-10 CA CA3030559A patent/CA3030559A1/en not_active Abandoned
  • 2017-07-10 EP EP17743122.8A patent/EP3482444A1/de not_active Withdrawn
  • 2017-07-10 WO PCT/US2017/041382 patent/WO2018013485A1/en unknown

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